Attention Deficit/Hyperactivity Disorder, Pediatric



  • Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that manifests in early childhood characterized by distractibility, impulsivity, hyperactivity, and/or inattention.
  • Three subsets: predominantly hyperactivity (ADHD-H), predominantly inattentive (ADHD-I), or combined (ADHD-C)
  • System(s) affected: nervous


  • Predominant age: onset <12 years; lasts into adolescence and adulthood
  • Predominant sex: male > female (2:1); ADHD-I is more common in girls.

9–15% of children 4 to 17 years old

Etiology and Pathophysiology

Not definitive—suggested pathogenesis includes imbalance of catecholamine metabolism and structural brain differences. Environmental influences are controversial.

Risk Factors

  • Family history (genetic component)
  • Medical causes (affecting brain development)—including prenatal tobacco exposure and prematurity

Commonly Associated Conditions

  • Mood disorders—depression, anxiety
  • Behavior disorders—oppositional defiant disorder, conduct disorder
  • Autism spectrum disorders
  • Physiologic disorders—sleep disorders, tics
  • Learning disabilities, developmental coordination syndrome, language disorder
  • Substance use disorders

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